Signed settings refactoring: Proper caching and more tests.

chrome/browser/chromeos/cros_settings_provider.h

Index: chrome/browser/chromeos/cros_settings_provider.h
diff --git a/chrome/browser/chromeos/cros_settings_provider.h b/chrome/browser/chromeos/cros_settings_provider.h
index c050092b22543076dd79392c880f6bccc48c1c29..ba65253a3f30a71a55feee707566379c61db4634 100644
--- a/chrome/browser/chromeos/cros_settings_provider.h
+++ b/chrome/browser/chromeos/cros_settings_provider.h
@@ -30,11 +30,14 @@ class CrosSettingsProvider {
   // was needed in which case the return value is false. Else it will return
   // true and won't call the |callback|.
   virtual bool GetTrusted(const std::string& path,
-                          const base::Closure& callback) const = 0;
+                          const base::Closure& callback) = 0;
 
-  // Gets the namespace prefix provided by this provider
+  // Gets the namespace prefix provided by this provider.
   virtual bool HandlesSetting(const std::string& path) const = 0;
 
+  // Reloads the caches if the provider has any.
+  virtual void Reload() = 0;
+
  private:
   // Does the real job for Set().
   virtual void DoSet(const std::string& path,